Support is requested for a Keystone Symposia meeting entitled Sensing and Signaling of Hypoxia: Interfaces with Biology and Medicine, organized by Peter J. Ratcliffe, L. Eric Huang, Michael Ohh and Cynthia M. Beall. The meeting will be held in Breckenridge, Colorado from January 7 - 12, 2014. Maintenance of oxygen homeostasis is a fundamental physiological challenge that is disturbed in most human diseases including diseases of the heart, lung and blood as well as cancer. Understanding the nature of cellular and systemic responses to low oxygen levels (hypoxia) is therefore of critical importance in physiology and medicine. This meeting will focus on advances in the understanding of the biochemistry and biology of hypoxia signaling and their impact on cell biology, physiology and medicine. Specific emphasis will be placed on the emerging interfaces of hypoxia biology with new areas of scientific progress including metabolic regulation, epigenetic signaling, stem-cell biology, inflammation, immunity, tissue repair and cancer. The meeting will also aim to link these processes to the integrative physiology of hypoxia and act as a forum for interfacing reductionist molecular approaches with medical physiology. Key objectives are: 1) to report key emerging research findings in hypoxia biology across a range of biomedical research fronts; 2) to promote and extend new areas of research into the impact of hypoxia on biological systems; and 3) to promote interdisciplinary research aimed at linking molecular and integrated physiology and defining therapeutic opportunities.